Like many parents of autistic children, I was hoping that it was all over. For the past eight years, the campaign against MMR has been at best a distraction from the important issues in autism - scientific research and matters of education and care provision. At worst, for many parents, it has raised - and dashed - hopes of compensation and forced many more to carry an utterly unwarranted burden of guilt over giving their children MMR.
A Cochrane review published last month concluded that there was "no credible evidence" of a link between the MMR vaccine and either inflammatory bowel disease or autism. This review, which followed a series of studies coming to the same conclusion, suggested that the scare launched by Andrew Wakefield's notorious Lancet paper in 1998 had reached the end of the road. Instead, it appears to have provoked a resurgence of the old controversy, with polemical exchanges between rival newspapers and a return of the familiar rancorous disputes on the internet.
All this brought me back to my first encounter with the MMR-autism thesis in 1998. My son was five and, though he had followed a course of apparently normal development before regression into autism at the age of 18 months, said to be typical of children affected by MMR, we had no recollection of when he had received his vaccination. On digging out his baby clinic book, we discovered that he had had the jab, without any apparent adverse effects, about four months before we first noticed the signs of his autistic withdrawal.
I carefully checked out the Lancet paper. Although the authors admitted that they "did not prove a causal relationship" between MMR and autism, it would be more accurate to say that they did not present any evidence of a causal relationship. They simply reported the conviction of the parents of eight of the 12 children in the study that there was such a link. Furthermore, the postulated four-stage mechanism through which MMR was supposed to produce autism appeared speculative. Putting this together, I was unimpressed with the theory that MMR was a factor in causing autism in my son or any child.
The remarkable divergence between the perception of the MMR-autism link in the worlds of science and public opinion is the key to the persistence of the controversy. A few weeks after the Lancet publication, the Medical Research Council brought together leading authorities and invited Wakefield and his colleagues to present their case. The inquiry concluded that there appeared to be no relation between trends in autism and the introduction of MMR, that the supposedly distinctive pattern of bowel inflammation identified by Wakefield was in fact a common and benign condition, and that the causal mechanism was "biologically implausible". From the outset, the scientific consensus was that the Wakefield report didn't prove anything. No paediatrician, paediatric gastroenterologist or autism specialist in the country believes it.
Meanwhile, in the media and wider British society, the conviction that MMR was responsible for a rising number of autism cases became widespread. More and more parents of children with autism joined the ill-fated anti-MMR litigation, and rates of vaccine uptake fell, particularly after Tony Blair's equivocation in December 2001 over whether his son Leo had received the jab. The campaign against MMR struck a chord when there was a heightened sense of individual vulnerability to a range of environmental threats - including GM foods, pesticides and other pollutants. It also appealed to sentiments of suspicion and distrust of science and medicine, of corporations (especially drug companies) and mainstream politicians, and a general mood of anger and resentment.
Over the past decade popular discontents have raged around a range of political issues - fuel prices, student loans, blood sports and the invasion of Iraq. Yet MMR provided a focus for protest that was both intensely personal and political. It brought together issues of health and child welfare that were already central preoccupations of a highly individuated society. The controversy over immunisation allowed scope for individual initiative - at least in the form of a gesture of defiance - that was generally lacking in the public sphere. If you could do nothing about the demise of politics, the apparent decline in social cohesion and civility, and the threat of bioterrorism and war, at least you could take a stand on the issue of MMR.
My son is now 13. He is much loved in the family, but he is still unable to speak and is inclined towards self-injurious and difficult behaviour. Having grappled with the inadequacy of respite services over the past decade, we were deeply moved by the plight of the 67-year-old mother recently convicted for killing her adult autistic son when she could no longer cope with his violent behaviour. I have not yet been driven to homicidal tendencies towards my son, but I have to confess that two questions, often innocently asked, may put members of the public at risk. These are "Has he got any special skills?" and "Do you think it was all caused by MMR?"
· Michael Fitzpatrick is a GP in London and the author of MMR and Autism: What Parents Need to Know
